This week, the PSU and the stepper motors arrived.

I decided early on in speccing out the printer that I wanted to go with a heated bed. It generates much higher quality prints, but with no need of a raft. One of the problems generated by having a heated bed, however, is that you need almost 20 amps of power. Each stepper motor (or more correctly, the stepper motor driver) is rated for about 2 amps, and the heated bed can use up to 9 amps when warming up. Add on the hot end, and you’re nearly at 20 amps when starting off a print. Fortunately for power bills, this drops down a lot once the hot end and bed are up to temp.

I contemplated going route of other people and modding an desktop computer ATX supply. But in the end I decided to go for this one. It’s cheaper than a ATX supply that’s rated for 20 amps, and I don’t need the 3v and 5v outputs. This PSU is designed to recharge batteries for radio-control vehicles, but it makes a good 12v lab bench supply.

Also arrived are some stepper motors from AusXMods. The specs on these are pretty good, get the full amount of torque required (50 Ncm) at low volts and amps. These motors should easily be able to handle the load required by the Prusa.